No use crying over old fashions and modesty that will never return, but it was so much easier to be attractive when we only wore jeans for cleaning house or picnics or playing softball. I assume this is an ad to encourage larger women to buy more jeans. Notice anything? All these women are gorgeous, young and well proportioned with long hair and beautiful skin. That leaves out about 3/4 of the female population. It's marketing--always remember that. It says, if you buy me, you too can look good, just like the ads with the skinny waifs. Nothing wrong with that as long as you understand the game.
Go to any workplace--choose the cafeteria so you don't know who works where. Notice the difference in the clothing of the men and women. Men will always look better dressed and more professional in khakis and a sport shirt than women dressed the same way. And in jeans, there's just no contest. Dress for the job you want.
I googled "career clothes large women," and found a few suggestions, all feminine and professional without looking slutty, but if you google "fashion large women" the images are just awful.